Pizza

I have my cam covers off and while I do I wanted to clean my oil check vales because at startup my car makes a ticking noise. I checked the WSM and Tony's site for the procedure. My 86.5 heads don't have a hole for the bolt to screw into. It's just a solid steel plug. I do feel the allen screw on the side of the engine though. What's up with that? Did the oil check valve start in 87?

Thanks

jon928se

Charles,

You have it right. The allen bolt holds the steel plug (I thought it was Alu but it is 4 years since I looked) in place. Plug has a groove around it's circumference allen bolt has a pointed end that locates in the steel groove. Undo the allen bolt about 4 turns and lift the plug out with a magnet. Real men pick the 928 up and shake it upside down! When you pull the plug out be very careful as there is loose spring and ball contained underneath it that will stick to the plug until you have lifted it high enough up for them to fall off down the oil return galleries into the sump!. It is wise to plug all the oil return galleries with clean rags before you start.

Clean the spring,ball and the ball seating (this is the non return valve). Most importantly put a new 'O'ring on the plug. This 'O' ring is what seals the oil gallery going to the lifters. If it leaks it allows the oil pressure in the lifters to flow back out in to the cambox area - causing the lifters to be noisy at start up.

I'ld guess that in most cases just replacing the O ring is all that is required, the cleaning just makes us feel happy.

Cheers Jon in NZ